Spring condition signal for a spring driven signaling box



March 1956 E. A. BRASS SPRING CONDITION SIGNAL FOR A SPRING DRIVEN SIGNALING BOX Filed June 12. 1952 wl i w AT rams/s Y United States Patent 2,737,645 R NG, COND TION SIGNAL FORA.

7 Claims. (came-29.2

This invention relates to improvements in signalling eq ipm n M er rti u er y h s inv nt on r s t imPIfDVBmcnts;in signaling equipmenhthat can be used in alarmcircuits.

It therefore an object-of-thepresent invention to providei llproved signaling equipment that. can; be, used in alarm circuits,

Inmany alarm circuits, and particularly in many fire alarm circuits, a number of signal boxes are connected in series with each other and with indicating equipment whichis locatedin a centralstation. Such alarmcircuits are frequently known as full; metallic alarm circuits. In such alarm circuits the signal boxes can be seto to interrupt the circuits and thus transmitsignals to the indicating equipmentin the central stations. The boxes customarily have spring-driven earns which actuate switches to interrupt and re-establish thecircuits, thus generating the required signals.

Thesignal. boxes ofsuch circuits are frequently provided with normally-open switches that can connect the carmoperated contacts with, ground through low-resistance paths; those switches closing whenever the mainspringsof the boxes run down or break, andalso closing-when the non-interfering magnets of the boxes become tie-energized One such box is shown and described in United States Reissuev Patent No. 22,514 of Frank R Bridges. The grounding-thatoccurs when the mainspringoi; such afbox" is runningdownhas been regarded as being de sirable becauseit enables the box tosignal even;th ough another box has seized the line; and the grounding that occurs when. the mainspring of sucha box breaks has, been regardedas being desirable because it-indieates that s m p t of the cu e d at e t o Howeve the grounding in eitherof theseinstances, cancoact-w-ith a. tre gro nd, aground in a-w a e a g untling u n he ox u o h m nspri g unn g do ner b e k n or agr un ing n anot erbQx-" ne to he. ti h giza ion f he n n-inter e n magne s-t0 r nd r h t intervening portion of thecirc uit dead; thus preventing igna ling by he rm xe h h interven ngpe ie ofthe circuit. Moreover whilethe groundingthat-oceurs whenthe m i p g b a s o nd c te tha s m part of the circuit needs attention, it does-notidentify that part; As aresult, time-consuming tests must beused-to determine (a) Whether the grounding is-in thelineitseli; or is in,a. box and (.b) the location.of-the=*boxif thegrounding isin a box. This,,of course, is, objectionable. The presentv invention obviates these objections by providing an alarmbox whichcan senda distinctive signal-to the control station through the ground whenever the Ina-in.- spring of that box breaks or runs downgbut which-does not. apply a continuous low-resistance ground; to the circuit. When that alarm box signals through the, ground, the. operator atthe central station can determine immediately whether the ground is in the lineitself ortis in a- QX. n can a od n mmediately h loc tion f h fb i the sroundis sin-a; box Itis: thereforean obiecto h p e ent i en -iehv top ovidelan alarmflbex which canzsend a distinctive signal through the, ground whenever the mainspring breaks or runs down, hut;3vhieh 2 does not-apply a continuouslow resistance ground to the circuit.

The alarm box'provided bythe present invention :has an actuator that; closes a shunt across the signaling circuit and that connects a vibrator, of predetermined frequency, to ground'whenever the mainspring breaks or runs. down. The shunt completes the. full metallic circuit for theother alarm boxes of the circuit; and the vibrator sends a signal, through the ground to a frequency indicating .dev16; t the central station, which distinctively. identifies that alarm box. Moreover, the combinedresistan'ce of the vibrator and the frequencyindicating device is high enough that the signal emitted by. the vibrator will not actuate the indicating device, at the central station, which responds to signals transmittedto ground through low resistance paths at boxes wherein the non-interfering magnets have become de-energized. It is therefore an ob.- ject of the present invention to provide a signalling-box with an actuator that shunts the signalling circuit and connects avibrator to ground when the mainspring relaxes.

The signalling circuit provided-by the-presentinvention has a central station with a frequency responsive meter .andwith a numberof signalling boxes that each emit a distinctively different signal when the mainspring relaxes, either by running down orby breaking. The distinctively different signals will be indicated at the centralstationon the frequency responsive meter and will enable prompt re.- .placement or. prompt windingof the mainspring which has either brokemorrun down. With-such a circuit, the operators will; knowirnmedia-tely when a mainspringis broken or has rundown andwill know-exactly which mainspring hasexperiencedsuch relaxation, This arrangement facilitates fulland immediate maintenance of all parts of the signalling circuit, It is therefore an -object of the-present invention to provide a signalling circuit which has a central: station equipped with a frequency responsive meter and which has a number of signalling boxes-with vibrators that emit. distinctively different frequencies when themainsprings of thoseboxesrelax. Other and furtherobjects and advantages of the present invention should becorneapparent from anexarninationof the drawing and ac p ny g e c p ion.

In the drawing and accompanying description a pre,

ferred embodiment of the presentinvention is shown. and described habit is tobe understoodthatthedrawing and accompanying description are for the purposeofillustration. only and do not limit the invention and that=the ve t on will. e defin d. vthe appended l m "the drawingis a schematic diagram of a signalling circuit. which-hasa central station; a; number of sign lin b x s h det ils efv wo o th s b re indicated in the drawing,

In th d aw ng he uts ra 1-9:. genera y d not s-asit nailing box; Thisbox has-a housing-Lifer a mainsprin-g 1d. The housing 1 2' has an opening 1'3'il1qthe W31lthPr of. The mainspring 14.is connected-toand-drives a rota-o ing shaft 16. A signallin-gcarn 18is mountedon the Shaft andis rotated by thatshaft. A- cam followerlfidsmountedon a pivot 22 adjacent the signallingcarn 1:8,; The cam follower will rotate about; the-pivot;-2;2 -inresponse tothe lobes onthe signalling carnlfl;

A leaf contact 24is disposed adjacentto carnfolloWer 2.0 nd bia the n o low rtowa d he; s nalling cam 18. A pair of follower contacts 26ers. adjacent the leaf o t et .endareb ased fo movemen to h u A afe 8 is djacent th llowe o t cts 2 and s e g ahle y one th se. tql ewer, contacts In. he positionof rest of the component parts of the box 111, asshown in the drawing, the cam follower 2 0; is held in engagement with the leaf-contact 251 the leaf contact 24*holds the follower contacts 26 in engagement with itself and with the leaf' contact 28.- The-cam follower-20 is held in engagement with the leaf contact 24 by one of the lobes on the signalling cam 18. When the cam 18 rotates, the cam follower 20 will be able to move in a clockwise direction to free the leaf contact 24 for movement away from the follower contacts 26 and to free the follower contacts 26 for movement away from the leaf contact 28. However, each succeeding lobe of the cam 18 will return the contacts to the closed circuit position shown in the drawing.

The box 10 has non-interfering coils 3'0 and 32. The coil is connected to the leaf contact 28 and the coil 32 is connected to the leaf contact 24. The mainspring housing 12, the mainspring 14, the shaft 16, the signalling cam 18, the cam follower 20, the pivot 22, the leaf contacts 24 and 28, the follower contacts 26, and the noninterfering coils 30 and 32 are constructed in a manner and form typical of the corresponding component parts of non-interfering signalling boxes. The construction and form of these component parts is not the essence of the present invention and therefore the details of the construction and form of these component parts is not given.

A junction 34 is provided between the non-interfering coil 32 and the box terminal 38 which is connected to one side of a full metallic signalling circuit. A junction 36 is disposed between the non-interfering coil 30 and the terminal 40 of the box which is connected to the other side of the full metallic signalling circuit. A leaf contact 42 is connected to the junction 36, and the leaf contact 44 is connected to the junction 34. The leaf contacts 42 and 44 are adjacent each other and can be made to engage each other. A leaf contact 46 is adjacent the leaf contact 44 and can be made to engage that leaf contact. Extending between the leaf contact 46 and the ground connection 48 is a vibrator 50 which has shading rings 52 and which has an armature 54. Shading rings 52 will preferably be of a non-magnetic material such as copper or aluminum and those shading rings will determine the rate at which the armature 54 of the vibrator 50 will open and close the circuit between the contact 46 and the ground connection 48. Whenever the vibrator 50 is energized, it will pull the armature 54 toward itself and thus interrupt the circuit; whereupon the armature 54 will move into circuit closing position under the action of a spring. As long as the circuit is closed, the vibrator 50 will continue to cause its armature 54 to make and break the circuit at a predetermined and distinctive rate or frequency.

An actuator 56 is mounted on a pivot 58 adjacent the housing 12 for the mainspring 14, and a lobe on the end of the actuator 56 extends through the opening 13 in the mainspring housing 12. An extension spring 60 engages the actuator 56 and biases that actuator for rotation in a clock-wise direction around the pivot 58. In its normal position, as shown in the drawing, the actuator 56 permits the leaf contacts 42, 44 and 46 to be spaced apart. However, that actuator will respond to a relaxation of the mainspring 14, either due to the running down of the spring or to a breaking of the spring, to rotate in a counterclock-wise direction to force the leaf contacts 42, 44 and 46 into engagement with each other.

The terminal 38 of the signalling box 10 is connected by the conductor 78 to a signalling box 68, which in turn is connected by a conductor 80 to a signalling box 70. The signalling box 70 is connected by a conductor 82 to the central station which has a fuse 90, a line relay 98 which operates a signalling device of usual form and operation, and which contains a rheostat 102. The central station also contains a battery 104, a rheostat 105, line relay 96, frequency responsive meter 106, ground connection 108, ammeter 94, and fuse 92. The fuses 90 and 92, the line relays 96 and 98, the rheostats 102 and 105, the battery 104, and the amrneter 94 of the central station are of usual construction and form. The frequency responsive meter 106 is of standard construction and form and can be either an electronic meter or a vibrating reed meter; but its use in a signalling circuit is unique. The central station is connected to a signalling box 72 by the conductor 88, the signalling box 72 is connected to a signalling box 74 by the conductor 86, and the signalling box 74 is connected to the signalling box 61 by the conductor 84. A conductor 76 connects the terminal 40 of the signalling box 10 with the terminal 38 of the signalling box 61. The circuit may have, and will usually have, a considerably larger number of signalling boxes than shown in the drawing; the number of signalling boxes indicated on the drawing being limited for clarity of illustration. Each of the signalling boxes will have a mainspring housing, a mainspring, a shaft, a signalling cam, a cam follower and pivot therefor, leaf contacts and follower contacts controlled by the cam follower, non-interfering coils, an actuator controlled by the mainspring, leaf contacts controlled by the actuator, and a vibrator connected between ground and one of the contacts controlled by the actuator. The only differences between the various signalling boxes of the circuit will be found in the signalling cams and in the characteristic frequency of the vibrators. The signalling cams of the various boxes will have different numbers and combinations of lobes, and the vibrators of the various boxes will have different numbers of shading rings 52.

The signalling box 61 is illustrative of a signalling box wherein the mainspring 64 has broken in the course of a signalling cycle. The cam follower 20 bears against the periphery of the signalling cam 66 rather than against one of the lobes on that cam and thus the leaf contact 24 is out of engagement with the follower contacts 26 and the follower contacts 26 are out of engagement with the leaf contact 28. This means that the series connected signalling circuit is broken and would thus be interrupted and dead. However, the relaxed spring 64 has rotated the actuator 56 in a counterclock-wise direction about the pivot 58 and against the force of spring 60 to press the leaf contacts 42 and 44 in engagement with each other. These leaf contacts close a normally inactive shunt circuit across the terminals 38 and 40 of the signalling box 61; thus closing the full metallic circuit and rendering it operative. The actuator 56 also presses the leaf contact 44 into engagement with the leaf contact 46, thus placing leaf contact 46 in engagement with both sides of the full metallic circuit. As a result, a circuit is completed from the battery 104 through both sides of the full metallic circuit to the contacts 46 and thence to ground through the vibrator 50 and its armature 54. The circuit returns to the battery 104 through the ground connection 108 at the I central station and through either side of the frequency responsive meter 106. The completion of the circuit through the vibrator 50 will cause that vibrator to emit a characteristic frequency which will be registered on the frequency responsive meter 106 at the central station. In this way, the operator at the central station will be given immediate knowledge of the relaxation of a mainspring in a signalling box and will also be given immediate information as to the identity of that box. This facilitates prompt replacing or winding of the relaxed mainspring.

The vibrator 50 will continue to emit its distinctive signal and that signal will continue to be indicated by frequency responsive meter 106. That signal will not interfere with the sending by any other box, through the ground of cam-controlled signals when the non-interfering magnets of those boxes become tie-energized because the combined resistance of the vibrator 50 and the frequency responsive meter 106 is so high that the vibratoremitted signal will not be strong enough to energize relay 96 or relay 98.

By having the leaf contact 46 engageable with the leaf contacts 42 and 44, the present invention assures the emission of the characteristic signal from the vibrator even if one half of the full metallic circuit is broken or grounded. In this way, full and complete safety is assured to the users of the signalling circuit provided by the present invention.

, said ground connection and said metallic Whereas the drawing and accompanying description have shown and described a preferred embodiment of the present invention, it should be apparent to those skilled in the art that various changes may be made in the form of the present invention without afliecting the scope thereof.

What I claim is:

1. In a spring-driven signalling box for use in full metallic signal circuits, a terminal connectible to one side of said metallic circuit, a second terminal connectible to the other side of said metallic circuit, a normally inactive circuit connected to said terminals, a normally open switch in said normally. inactive circuit, a ground connection, a second normally open circuit extending between circuit, a signal-emitter and a second normally open switch in said second normally open circuit, said signal-emitter responding to closure of said second normally open circuit to generate a continuous signal of a frequency that is distinguishable from and will not interfere with the normal signals from said box or other boxes, said second normally open switch responding to closure of said second normally open circuit to apply said continuous signal to said metallic circuit, and an actuator that is adjacent the spring of said box and is movable by relaxation of said spring to close the first said and said second switches to connect the said one and the said other sides of said metallic circuit and to connect said metallic circuit to ground through said signal-emitter.

2. In a spring-driven signalling box for use in full metallic signal circuits, a terminal connectible to one side of said metallic circuit, a second terminal connectible to the other side of said metallic circuit, a normally inactive circuit connected to said terminals, a normally open switch in said normally inactive circuit, a ground connection, a second normally open circuit extending between said ground connection and the first said normally open circuit, a signal-emitter and a second normally open switch in said second normally open circuit, said signalemitter responding to closure of said second normally open circuit to generate a continuous signal of a fre quency that is distinguishable from and will not interfere with the normal signals from said box or other boxes, said second normally open switch responding to closure of said second normally open circuit to apply said continuous signal to said metallic circuit, and an actuator that is adjacent the spring of said box and is movable by relaxation of said spring to close the first said and said second switches to connect the said one and the said other sides of said metallic circuit and to connect both sides of said metallic circuit to ground through the first said normally open circuit and through said signalemitter.

3. In a spring-driven signalling box of the non-interfering type for use in full metallic signal circuits, a terminal connectible to one side of said metallic circuit, a second terminal connectible to the other side of said metallic circuit, a normally inactive circuit connected intermediate said terminals and the non-interfering coils of said box, a normally open switch in said normally inactive circuit, a ground connection, a second normally open circuit extending between said ground connection and said metallic circuit, a signal-emitter and a second normally open switch in said second normally open circuit, said signal-emitter responding to closures of said second normally open circuit to generate a continuous signal of a frequency that is distinguishable from and will not interfere with the normal signals from said box or other boxes, said second normally open switch responding to closure of said second normally open circuit to apply said continuous signal to said metallic circuit, and an actuator that is adjacent the spring of said box and is movable by relaxation of said spring to close the first said and said second switches to connect the said one and the said other sides of said metallic circuit and to connect said metallic circuit to ground through said signalemitter.

4. In a spring-driven signalling box for use in signal circuits, a terminal connectible to a signal circuit, a ground connection, a normally inactive circuit between said terminal and said ground connection, a signal-emitter and a normally open switch in said normally open circuit, said signal-emitter responding to closure of said normally open circuit to generate a continuous signal of a frequency that is distinguishable from and will not interfere with the normal signals from said box or other boxes, said normally open switch responding to closure of said normally open circuit to apply said continuous signal to said terminal, and an actuator that is adjacent the spring of said box and is movable by relaxation of said spring to close said spring and connect said signal circuit to ground through said signal-emitter.

5 In a full metallic signal circuit which has a plurality of spring driven alarm boxes, a metallic conductor extending between and connecting said alarm boxes, and a frequency response meter, the improvement which comprises a connection between said meter and one side of said circuit, a connection between said meter and the other side of said circuit, a connection between said meter and ground, a frequency transmitter in each of said alarm boxes that transmits a signal of different frequency than the signal transmitted by the frequency transmitter of every other said alarm box, and of a different frequency than the normal signals of each said box and said other boxes, a connection between said frequency transmitter and ground, a normally open connection between said frequency transmitter and said one side of said circuit, a normally open connection between said frequency transmitter and said other side of said circuit, and an actuator that closes said normally open connections when the spring of said alarm box relaxes.

6. In a full metallic signal circuit which has a plurality of alarm boxes, a metallic conductor extending between and connecting said alarm boxes, and a frequency response meter, the improvement which comprises a connection between said meter and said circuit, a connection between said meter and ground, a frequency transmitter in each of said alarm boxes that transmits a signal of a different frequency than the signal transmitted by the frequency transmitter of every other said alarm box, and of a different frequency than the normal signals of each said box and said other boxes, a connection between said frequency transmitter and ground, a normally open connection between said frequency transmitter and said circuit, and an actuator that closes said normally open connection when the spring of said alarm box relaxes.

7. In a metallic signal circuit which has a plurality of alarm boxes, a metallic conductor extending between and connecting said alarm boxes, and a frequency response meter, the improvement which comprises a connection between said meter and said circuit, a connection between said meter and ground, frequency transmitters in said alarm boxes, said frequency transmitters being adapted to provide a plurality of different signals that are distinctively different from and will not interfere with the normal signals from said boxes, normally open switches between said frequency transmitters and ground, and actuators that selectively close said switches, said frequency transmitters being magnetically shaded circuit interrupters of selectively different shading.

References Cited in the file of this patent UNITED STATES PATENTS 615,723 Baron Dec. 13, 1898 760,955 Callum May 24, 1904 883,665 Nolen Mar. 31, 1908 970,887 Cole Sept. 20, 1910 2,388,531 Deal Nov. 6, 1945 2,456,038 Young Dec. 14, 1948 2,574,458 Atkinson et al Nov. 13, 1951 

